Communication networks may include network switches. A network switch connects a communication device with a network router or other communication device. A transmission line, such as a copper cable or an optical fiber, may be used to transmit data between the network switch and the network router. The transmission line may be coupled with an interface of the network router. The interface may become inactive, for example, when the transmission line is disconnected from the network router or network switch. When the interface is inactive, the network switch is unable to communicate with the network router. Accordingly, the communication device, which uses the network switch to communicate with the network router, is unable to communicate with the network router or the other networks connected to the network router.